It can be appreciated that spinal rods have been in use for years. Typically, spinal rods are comprised of rods constructed from titanium and stainless steels. However, one problem with a conventional spinal rod is that the rigidity of the rod makes contouring the rod difficult and time consuming to insert into the spine. Another problem with conventional spinal rods is the inability to perform multiple level fusions through a minimally invasive approach. Still another problem with conventional spinal rods is that the required contouring of the rod to meet patient anatomy often creates a non-uniform bend or bends (i.e. kinks) that decrease the strength of the rod.
In spinal fixation, screw or hook components are attached to the spine and connected to a rigid rod. This allows the alignment of the spine to be adjusted and/or held in a specific manner to allow fusion to occur. However, the natural anatomy of the spine does not allow hooks and screws to be connected in a straight line. The lordotic curve requires that a rod be contoured to match this lordosis, particularly on multiple level fusions. In addition, the pedicies vary in location and angle such that screws placed in the pedicles do not always line up in multiple level fusions. Therefore, for proper connection of all spinal components while maintaining the natural curvature of the spine, the rod must be contoured in multiple planes. In addition, this becomes much more difficult for minimally invasive surgical techniques, where the rod is inserted into the spinal components through a minimal incision. The rod has to be very carefully contoured, and the number of levels or vertebrae fused must be kept to a minimum. Although systems exist to help template and guide the rod into screw bodies, these procedures are limited and are often difficult and time consuming. Although these devices may be suitable for the particular purpose to which they address, they are not as suitable to provide a device that reduces or eliminates rod contouring during insertion while providing sufficiently rigid support of a spinal implant system.